Internal-combustion-engine piston



Nwm 2 W260 W. B. EARNSHAVI INTERNAL COMBUSTION ENGINE PISTON Filed Oct. 5. 1923 Mr? [Timer-12F JQhiZiifam a H25 :QZZDFHE Patented Nov. 2, 1926.

UNITED STATES? PATENT OFFICE.

WILLIAM B. EARNSHAW, OF DAYTON, OHIO, ASSIGNOR TO GENERAL MOTORS RE- SEARCH CORPORATION, OF DAYTON OHIO, A CORPORATION OF DELAWARE.

IN TERNAL-OOMBUSTION-ENGINE PISTON.

Application filed October 3.19%. Serial macaw.

The present invention relates .to pistons for internal-combustion engines and more particularly topistons of the so-called composite or bimetallic type.

a light weight piston having the heat characteristics of aluminum or its alloys, and the expansion and wear characteristics of cast iron. f

Another object is to simplify the making and assembly of such pistons.

Further objects and advantages of the present invention will be apparent from the following description, reference being had 15 to the accompanying drawing, wherein a preferred form of embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a view inelevation'of. the piston with part in vertical section along the axis of the pin bosses.

Fig. 2 is a view-similar to Fig. 1 but taken at right angles.

Fig. 3 is a bottom plan view of the piston.

' As'indicated in the drawings, the piston is composed of two portions, one of which;

the head portion 10, is cup-shaped and provided upon its outer periphery with grooves 11 for packing rings and hasinside the cup two bosses 12 drilled longitudinally and counter-sunk for screws 13of which there are also two as indicated in dotted lines in Fig. 3.

The other portion of the piston or skirt portion 15 is preferablya cylindrical casting having an inturned flange 16 at its upper end, which flangeis provided with a flatupper surface and adapted to fit tight-v ly against the lower edge of the cup-shaped head. Skirt portion 15i s also provided with pin bosses 17 and above these with lugs 18' whi h are drilled and threaded as at 19 for the reception ofscrews 13. Skirt pottioiilflfihas its upper outer edge 20 beveled,asf'indicated, and drilled as at 21. several of these drilled l 1 ole"s'-bei,ng provided although only oneis shown. This portion '15 is also provided with a ring groove 22 in which a ring may be placed for thepurpose of retaining the piston pin. It will'be noted that the lower edge of the head portion has in its outer periphery i Among the objects of the invention is" an L-shaped groove 25. This in conjunction with the outer edge of the upper surface of flange 16 forms another ring groove. In this groove there-is adapted to be placed an oil scraper ring and the bevel 20 is-provided to form an annular groove immediately underneath for the collected oil. From this groove the oil runs to the interior of the piston through holes 21.

-The skirt portion 15 is also preferably formed of less diameter longitudinally of the piston pin than at right angles thereto. This may be accomplished by grinding away some of the metal as is indicated at 30.

It is to be understood that while the metals mentioned and form shownare to be preferred, other metals and other forms may be substituted within the scope of the claims which follow.

What I claim is'as follows:

1. A two part piston comprising a cup shaped head portion carrying a complete ring groove and having its lower. outer edge forming a part of another ring groove; a skirt portion, the upper end of which completes the last. mentioned ring groove and is so formed as to provide a space for collecting oil; piston pin bosses carried-by said skirt portion; and two screws extending through said head portion and intosaid piston pin bosses for fastening said head and skirt portions together.

2. A two-part piston comprising a cupshaped head portion carrying a complete ring groove and having its lower outer edge forming' a part of another ring groove; a cylindrical skirt portion of which the unper end completes the last mentioned ring groove and providesa space for collecting oil, means being provided for draining said oil; and means for securing, the portions together. a In testimony whereof I hereto aflix my signature. 1

WILLIAM B. EARNSHAW. 

